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Date: Fri, 25 Sep 2009 18:39:29 -0700
Message-ID: <8a02878f0909251839g655b83aak3bd01ee753dc2cac@mail.gmail.com>
Subject: Re: couchdb: suitable for this type of applications ?
From: Jesse Hallett <hallettj@gmail.com>
To: user@couchdb.apache.org
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I am not sure how this applies to attachments; but with basic docs whenever
you update CouchDB does store a new version.  When you compact the database
it removes all but the most recent version of each document.  So compact the
database once in a while and your disk usage should be reasonable.

You can update whatever document properties you like and attachments will
attach to the new version of the document.  The attachment is not copied - I
believe attachments are stored separately and each document version gets a
reference to the attachment file.

I don't know enough off-hand to address the frequent small updates question.

On Sep 25, 2009 6:29 PM, "go canal" <gocanal@yahoo.com> wrote:

Hello,
another question. here is the use case:
 - a group of 10 engineers working on a project,
 - total files created over 12 months: 500
 - average update per file 15 times
 - average file size 20MB
 - file format: MS Office, PDF, CAD drawings.

I thought CouchDB is designed to support this type of applications but is it
correct to say that, every time there is an update to a doc, CouchDB will
create a new version of the (whole) document ?
So can I say the total storage will be 500 * 20MB * 15 = 150GB without
counting other overhead ?


Another question, if I only modify one field, is the attachment also copied
into the new version of the document ?

I also saw this message posted almost a year ago, talking about if CouchDB
is suitable for frequent small writes application, and it seems that some
client side buffering is needed :
http://markmail.org/message/klrbkh36ivxg46ax

Is it still true today ?

rgds,
canal

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